This is also the term which describes the conception of the Greek hero Perseus. Perseus was the son of Danae, who was blessed by Zeus's "golden shower" while held captive in a tower (since she was to bear a son who would kill her father, as Perseus later did). Whether the "golden shower" is referring to semen, or urine, or actual gold (as Gritchka suggested), and whether it's a sexual act, a type of rain, or objects falling from the sky is beyond my expertise. I must admit, though, that that is one hell of a way to get pregnant.